The installation of electrical wiring and equipment may be governed by standards adopted by local government that codify requirements for safe electrical installations. For example, a National Electrical Code (“NEC”) standard adopted in 2011 specified that field wiring of a building involves running of a neutral wire to a junction box. Jurisdictions implementing the NEC standard adopted in 2011 may require that an electrical device must be powered through a neutral wire if the device has the capability to be powered through the neutral wire. An electrical device can be powered through a neutral wire by connecting a line (or “hot”) wire carrying current from a power supply to a first terminal or other conductor of the device (i.e., the line terminal) and connecting a second wire from the power supply to a second terminal or other conductor of the device (i.e., the neutral terminal). Current can flow from hot wire to the line terminal through one or more loads in the device, such as circuitry powered by the current, and to the neutral wire from the neutral terminal.
In buildings or other structures that are not wired in compliance with the 2011 NEC standard, electrical devices can be installed that are powered through ground. An electrical device can be powered through ground by connecting a hot wire from a power supply to the line terminal and connecting a second terminal or other conductor of the device to ground. Current can flow from the line terminal through one or more loads in the device to an earth ground.
Prior solutions for powering devices, such as a sensor, that may be installed according to electrical standards involve powering the device either through a dedicated neutral wire or through a dedicated ground wire or terminal. Powering the device either through a dedicated neutral wire or through a dedicated ground wire or terminal can require an installer of an electrical device to select between a neutral-powered version of the device and a ground-powered version of the device. Requiring the installer to select between a neutral-powered version of the device and a ground-powered version of the device may require the installer to maintain duplicative inventory. An installer erroneously selecting the wrong version of the electrical device for a building may cause installation delays and increased installation costs for electric devices.
It is desirable to provide a single electrical device that is configured for selectively being powered through either a neutral wire or an earth ground.